A. Human sensory ganglia and spinal cord of fetal origin are cultured and characterized using nerve cell specific markers and autoradiography. Neurite growth of postmitotic sensory neurons is enhanced specifically by mouse nerve growth factor (NGF) and the adhesion molecules laminin and fibronectin. Synergism between NGF and laminin results in the three-fold increase of neurite length. B. Neurotropic viruses: human fetal spinal cord cultures infected with measles virus develop extensive fusion and virus production in non-neuronal (NN) cells while neurons do not show infection until much later. Addition of antiviral antibodies to the cultures results in prolonged infection of NN cells with sparing of neurons. Viral assembly of a rhabdovirus is studied with monoclonal antibodies to 3 viral proteins: the glycoprotein G, the membrane protein M, and the nucleocapsid protein N, and each of them display different intracellular. C. Immunocytochemical studies of peripheral myelin: P2 protein is located throughout Schwann cell cytoplasm and at the major dense line of compact myelin and myelin associated glycoprotein plays a role in maintaining periaxonal space. Sural nerve biopsies from paraproteinemia patients with neuropathy show axonal and not demyelinating lesions.